TRAJECTORY CORRECTION USING IMPULSE THRUSTERS FOR CONVENTIONAL ARTILLERY PROJECTILES

摘要

Six degree-of-freedom simulations were performed on a 105 mm C132 artillery projectile using the CONTRAJ module of PRODAS. The objective of this study was to determine the impulse thrusters' configurations that yield the best control authority and thus the greatest amount of correction on the projectile trajectory. It was also desired to explain the underlying physical reasons for the varying performance of the impulse thrusters. Contrary to finned projectiles, spin stabilized projectiles exhibit a gyroscopic response 90 degrees out-of-phase with the direction of the perturbation force. This renders the prediction of the thruster's impact on the projectile's trajectory much more difficult. Results indicated that locating the impulse thruster at or aft of the center of gravity provides greater drift correction for a given impulse magnitude. Reasons for this behaviour are explained. It is also shown that impulse thrusters with a burning intensity between 15 and 20 Ns would provide adequate course correction for a 105 mm artillery projectile. The use of several impulse thrusters along the trajectory of the projectile was investigated and shown to increase significantly the amount of correction achieved in drift.